The 6 Creepiest Things Hiding in Your DNA

#3. Grandparent-Based Death Time Bombs

We've mentioned before that your father's smoking could have made you fat. What we didn't mention, though, was that your grandparents' actions could also have doomed you to a short and unhappy life. Man, what did you do to piss off all of history? 'Cause it sure seems to hate the crap out of you.

A study in Sweden revealed a strange pattern in a rural community that had gone through periods of both famine and abundance in the 19th century. The study found that the grandsons of men who'd had childhoods coinciding with abundant years -- i.e., the ones who had stuffed their faces with grain for a season or two -- had a life expectancy of 32 years less than the grandsons of those who had experienced famine, with the deaths caused mainly by diabetes, heart disease and presumably the shame of having extremely fat grandparents. Daughters with gluttonous grandmothers suffered a similar fate.

Luckily, this delayed-reaction DNA sabotage doesn't always have to be negative: Mice exposed to "enriched" learning environments developed an improved memory that was passed on to offspring that had never experienced it. Man, it seems like just about anything you do with your life now has a serious impact on the genetics of later generations. So it's a good thing you're snacking on broccoli and stimulating your mind with such an esteemed source of learning on your way to save that orphanage, right?

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#2. Bug Poop

The assassin bug of South America lands on the faces of sleeping humans and sucks their blood while pooping on them at the same time, proving once again that nature is a sick and murderous pervert. Wait, did you just have a seizure? Weren't you reading an article on DNA? What the hell are we doing talking about bugs? Oh, God, there aren't bugs in your DNA, are there?! Relax, relax, it's nothing like that: It's just a parasite that lives in the poop floating in your bloodstream.

See, when the bug's victim scratches the bite, the crap sitting on the wound enters his system. And since assassin bugs carry the parasite T. cruzi, you get a free bonus prize with your shit-blood: Chagas disease. This condition can severely damage the heart and digestive system, producing, among other things, a symptom known as "enlarged colon." It's responsible for about 20,000 deaths a year, mostly in South America, but it occasionally pops up in the U.S. as well. Researchers who deliberately infected chicken eggs with T. cruzi and then tested the offspring of the infected chickens that emerged found that not only did those chickens have the parasite DNA, but so did their offspring, and so on.

Photos.comAnd all of their omelets tasted like shit.

But keep in mind that T. cruzi isn't necessarily the only parasite in our DNA, just the first we've discovered. Your cells might literally be swarming with the stuff. Hey, it's survival of the fittest. You know the old saying: If you can't beat 'em, take a dump in their veins and live forever in their children. If you don't believe us, just ask Charles Darwin. Oh, wait, you can't: Chagas disease is thought to have been the illness that killed him.

#1. The Twin That You Murdered as a Fetus

Regular Cracked readers probably know by now that babies are capable of murder in the womb, because that's our end goal: teaching you things that you can never un-know. But even womb murder isn't the end of the story. In some cases, you can end up absorbing your newly dead twin and having its DNA live on inside you, a condition known formally as "chimerism" and informally as "what happens when God stays up late watching movies by David Lynch."

Who just happens to be a Chimera himself.

In 2002, a woman named Lydia Fairchild submitted DNA tests for her three children as part of a welfare claim, only to have the results prove that genetically, she wasn't the mother. Since DNA is considered the gold standard of medical evidence, she was accused of somehow stealing the children, even after the poor woman gave birth to another "nonrelated" child right in front of a social worker. Finally, more extensive testing unlocked the mystery: Her ovaries had a different set of DNA than her bloodstream. In other words, she'd given birth to her dead sister's children. And then, presumably, she never stopped screaming.

Again, that's no fluke: In another case, a woman getting typed for a kidney transplant found out that one son was genetically hers, while two more belonged to her similarly dead sibling. A teenage boy being treated for an undescended testicle turned out to be carrying an ovary on that side from a twin sister -- as if an undescended testicle wasn't going to get him made fun of enough, now he's half ghost-woman as well? Jesus, screw you too, genetics. Chimerism is thought to be rare but also massively underdiagnosed, since it's undetectable outside of DNA testing, which doesn't happen to normal folks all that often. Potential symptoms can include slightly different-colored eyes, uneven skin pigmentation and waking up at night to find 'YOU KILLED ME' written on the bathroom mirror just before being strangled by your own reflection.

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